How is the germ removed from rice? A Comprehensive Guide to Rice Milling

November 19, 2025 •

3 min read

According to the USA Rice Federation, all white rice begins as brown rice, but the difference lies in its processing. The milling process, which removes the outer bran and germ layers, is the answer to the question, "How is the germ removed from rice?". This critical step increases the grain's shelf life but also changes its nutritional profile significantly.

Quick Summary

The rice germ is removed during the commercial milling and polishing process using specialized machinery. Starting with brown rice, the outer layers are stripped away via friction and abrasive techniques, leaving only the starchy endosperm for white rice production.

Key Points

Milling removes the germ: The rice germ is commercially removed through a mechanical milling and polishing process that also strips away the bran layer to produce white rice.
Pre-cleaning protects machinery: The process starts by pre-cleaning the paddy to remove all foreign particles like stones and dust, which prevents damage to the milling equipment.
Husking reveals brown rice: A rice huller is used to remove the inedible outer husk, leaving the brown rice grain intact with its nutrient-dense bran and germ.
Whitening removes bran and germ: Specialized whitening machines use abrasive or friction rollers to abrade the bran layer and germ from the brown rice.
Polishing enhances appearance: An optional polishing step gives the milled rice a shiny, lustrous finish preferred by some consumers.
White vs. Brown rice difference: Polished white rice has a longer shelf life and softer texture, but unpolished brown rice retains more fiber, vitamins, and minerals.
Byproducts are valuable: The rice germ and bran, removed during milling, are rich in protein, oil, and nutrients and are often used in supplements or feed.

The Step-by-Step Milling Process

The journey from harvested paddy to the polished white rice we find in stores is a multi-step industrial process. The commercial removal of the rice germ is a key part of this journey, transforming a nutrient-rich whole grain into a refined product. Here is a breakdown of the key stages:

Step 1: Pre-cleaning the Paddy

Before milling begins, the harvested paddy—or unhusked rice—must be cleaned thoroughly. This initial stage uses a series of sieves, air aspirators, and magnetic separators to remove foreign materials such as stones, dust, straw, and metal debris. This step is crucial for protecting the delicate milling machinery and ensuring the purity of the final product.

Step 2: Husking or Dehulling

Next, the cleaned paddy is sent to a rice huller or husker. These machines remove the inedible outer shell, known as the husk, to reveal the brown rice grain inside. The husking process typically uses rubber rollers that rotate at different speeds to gently tear the husk from the grain with minimal breakage. An aspirator is often used at this stage to separate the lighter husks from the heavier rice kernels. The resulting product is brown rice, which still contains its bran layer and germ.

Step 3: Whitening or Abrading

Once the brown rice is separated from the unhusked paddy, it moves to the next stage: whitening. This is where the germ and bran layer are removed. Rice whitening machines use abrasive or friction techniques to mill the outer layers off the rice kernel. The grains are rubbed against a rotating abrasive surface, such as an emery roller, which gradually scrapes away the bran. The speed and pressure of this machine can be adjusted to control the degree of milling and polishing.

Step 4: Polishing for Appearance

For some commercial operations, an additional polishing step is performed to give the rice a lustrous, shiny appearance that consumers often prefer. This is achieved using rice polishing machines, which can use water mist and friction to buff the grain's surface. This process further refines the rice and prepares it for the next step.

Step 5: Grading and Sorting

Finally, the milled and polished white rice is sorted and graded based on size, shape, and overall quality. Rice graders separate whole grains from broken kernels. High-tech optical sorters may also be used to remove any discolored or imperfect grains, ensuring a uniform and consistent final product that meets high consumer standards.

Comparison: White Rice vs. Brown Rice

The difference in processing has significant implications for the final product's nutritional value and properties. The removal of the germ and bran to create white rice results in some key distinctions..


Feature	Polished White Rice	Unpolished Brown Rice
Processing	Germ and bran layers are removed through extensive milling.	Retains the fibrous bran and nutritious germ layers.
Nutritional Profile	Lower in fiber, B vitamins (B1, B3, B6), magnesium, manganese, and antioxidants.	Significantly higher in fiber, magnesium, manganese, selenium, and B vitamins.
Glycemic Index	Higher, causing blood sugar to rise more quickly.	Lower, promoting slower and more stable blood sugar levels.
Texture & Taste	Softer, smoother, and milder in flavor.	Chewier and firmer with a distinct nutty or earthy flavor.
Cooking Time	Cooks more quickly and more evenly.	Takes longer to cook due to the intact fibrous layers.
Shelf Life	Longer shelf life because the oily germ has been removed.	Shorter shelf life as the natural oils in the bran and germ can go rancid.

Conclusion

The germ is removed from rice through an advanced, multi-stage commercial milling process that separates the outer layers of the grain. The entire procedure—from initial cleaning to husking, abrading, and polishing—is designed to create the uniform, white rice kernels that are widely consumed. While the extensive milling process extends shelf life and creates a softer texture, it also strips away a significant amount of the grain's fiber and nutrients, which are retained in brown rice. The choice between polished white rice and unpolished brown rice ultimately comes down to a balance of consumer preference for taste, texture, and nutritional content. For those seeking maximum fiber and vitamins, brown rice is the superior option, but white rice remains a culinary staple globally.

Understanding the Rice Milling Process

Frequently Asked Questions

The rice germ is the small, nutrient-rich embryo of the rice grain. It is a component of the whole grain, along with the fibrous bran layer and the starchy endosperm.

The germ is removed to increase the rice's shelf life. The natural oils found in the germ and bran can turn rancid over time, which would shorten the product's storage stability.

Commercially, the germ is removed during the milling process using abrasive or friction-based whitening machines. These machines rub the brown rice kernels against surfaces to strip away the outer bran and germ layers.

The main difference is in the processing. Brown rice is a whole grain that retains its bran and germ, while white rice has had these outer layers, and thus the germ, removed.

After the germ and bran are removed, they become a byproduct of the milling process. This nutrient-rich material is often used for feed or processed for nutritional supplements and oils.

Yes, a significant nutritional difference exists. Removing the germ and bran reduces the rice's content of fiber, B vitamins, magnesium, and other minerals.

Yes, rice germ is highly nutritious and can be consumed. It is rich in protein, essential amino acids, fiber, and vitamins like E and B. Some products, like haiga-mai (germ rice), are only partially milled to retain the germ.